Magnetic conveyer



a Get. 17, 1950 MERRlLL 2,526,253

MAGNETIC CONVEYER Filed Oct. 28. 1947 2 Sheets-Sheet 1 INVENTOR.

Homer 0. Merrill ATTQRNEY Oct. 17, 1950 MERRlLL I 2,526,253

MAGNETIC CONVEYER Filed Oct. 28, 1947 2 Sheets-Sheet 2 INVENTOR. 35 /-/omer 0. Merrill BY 4 M Q 4/ J g ATTORNEY Patented Oct. 17, {950 UNITED? STATES PATENT OFFICE; Q, j 2,526,253 r J MAGNETIC CONVEYER Homer D. Merrill, Berkeley, Calif. Application October 28, 1947, Serial No. 782,479

I 3 Claims.

1 This invention relates to conveyors and particularly to conveyor carriages utilizing permanent magnets to support and carry articles of magnetizable (usually ferrous) materials.

Carriers using magnetismf to support and hold articles of a magnetizable nature have a-number of advantages. One of these is the ability to 'hold the article without marring the metallic surface or the finish which has been applied thereto. The usual articles of this type with which I am familiar however, have employed electro-magnets. In the operation of an endless conveyor system these electro-magnets will be energized duringlsuch portion of the con veyor travel as ittis desired to supportthe articles and deenergized atittherpointwhere the articles are to be released. ."I-here are 'a number of objections to these arrangements; for one, the current required is'an item of expense; for, another, the switching' contacts are liable to get out of order, which'may resultindropping the articles conveyed .or' alternatively,'failure to release at theproper poi'ntx Current failure, of

course, renders the entire device inoperativej In certain specific applications for example, the use of such. a conveyor in spray painting with'volatile .and inflammable solvents, there is encountered the special problem'of avoiding sparking of the contacts with'the' attendant danger from fire or explosion. I

The present invention avoids all of these above-mentioned difficulties encountered in electro-magnetic systems by the-useof permanent magnets with eith'er. a. mechanicallor magnetic means to release the hold of the magnets on the articles carried.

netic conveyor carriage which is freelfromf the objectionable characteristics of electro-inagnetic carriages, but retains the advantages inherent in the-use of magnets.

Another object is to provide an eflilcient and mechanically soundmagnetie conveyor for articles which will-release the articles at the desired An object of my invention is tofprovide a mag-.

. 2 Figure 4 is a plan of a carriage having mechanical release means. 7

Figure 5 is a side elevation of the carriage shown in plan in Figure 4. 5 Figure 6 is a section along line 6-7-5 of Figure 4.

Figure 7 is a section onthe line 1.-1, Figfure 4. Referring first to the device shown in Figures 10 1, 2 and 3, the carriage is referred to generally by the numeral ID. A hanger H and rollers l2 support the carriage for movement along a track .'I3,,said' movement being imparted by a chain indicated at M. I 1

The means for holding the article, which is -in this instance a rather large-flat-bottomed steel pan, comprises the plurality (6) of horseshoe magnets l5 secured to the framework of "the carriage I0. The poles of the magnets are -in a common plane, though to hold other articles they may be diiferently located to suit the .shape of the article. Pivoted to the framework by means of jourinals 16 on each side of the carriage are magnet holders [1, shown best in Figure 3. Each holder includes a lever arm I8 upon which is mounted .a roller 19. Secured to the holder I! there are ,plurality of releasing or short-circuiting magnets 20 numerically equal to and cooperating with the holding magnets. As indicated in full alines in Figure 3 the normal position of the releasing magnets is out of contact with the hold- :ing magnets. At the point along the main track o1-.the conveyor at which it is desired to release ,35 the article, there are provided on each side of .the main track auxiliary tracks 2| so located and disposed as to cause the levers l8 to'assume the "positionindicated' in dotted lines of Figure 3 of the magnet holder :H. Springs, not shown, may

40 be used to keep the rollers I9 in contact with ftheetracks 21... a r a r P The magnets hold the-iron or other magnetizable material articles by the passage of the lines of force betweenuthe two poles of each magnet throughthe'materiaLof the'article. When the stantially stronger. Where this is the case, when the short-circuiting magnets are brought into contact with the holding magnets, the reversed poles will react with a temporary residual magnetism in the article so that the article is not merely released but is positively rejected.

In the embodiment of the invention illustrated in Figures 4 through 7, the carriage is indicated generally by the reference numeral 30. This carriage is supported by the hanger 31 and rollers 32 on the track 33 and is moved along the track by a chain which is not shown but which is similar to chain [4 in Figures 1, 2 and 3.

The holding means in this embodiment comprises a plurality of bar magnets 34, all oriented alike as regards their north and sourth poles. Angles 35 and 36 are secured tightly to the ends of the bars by through bolts 31. Since the angles 35 and 36 are the common steel angles having a fillet in the corner, they are further secured to the bar magnets through bakelite or other nonmagnetic material spacers 38. The effect of these angles is that they constitute pole pieces providing a continuous south pole on one side of the carriage and a continuous north pole on the opposite side of the carriage.

Slidably mounted in the carriage 30 by means of the rods 39, sliding in sleeves 40 shown in Figure 7, there are two bars 4| preferably of non-magnetic material and having their faces substantially in the plane of the bottom sides of the angles 35 and 36. The relation of these bars to the pan shown in dotted lines is indicated most clearly in Figure 6.

- Secured to the bars 4! at the center of the carriage there are uprights 42 to which are secured rollers 43. These rollers operate in a cam track 44 secured by frame structure 45 to the main track 33. A section of the cam track 44 is curved downwardly as indicated at 46 in Figure 5. When the carriage has reached the point at which the rollers 43 engage the section 46 on the track, the bars 41 will be pushed downwardly to force the supported article from the field of force of the magnets.

The cam track 44 may be continuous or may exist only in short sections at points at which the articles are to be released. In such instance, means will be provided to hold the bars 4! in their uppermost position. For example, the bars may be held up by springs or by friction means between the rods 39 and the tubes 40.

It will be obvious that many changes may be made within the scope of the invention. For example, instead of having a mechanical release mechanism in the form of the device shown in Figures 4 through 7, short-circuiting bar magnets may be used in'a manner like thatin which the releasing horse-shoe magnets. are used in the device shown in Figures 1 to 3 inclusive. Likewise, a mechanical releasing mechanism could be utilized in connection with the horse-shoe magnets.

It will be seen therefore that I have provided a conveyor and particularly a magnetic carrier or conveyor-carriage which is obnoxious to none of the objections applicable to electro-magnetic devices for the like purposes.

I claim:

1. In a conveyor, a track, a carriage for travel on said track, permanent magnets on said carriage for supporting articles of a magnetic material, shortcircuiting means for said magnets carried on said carriage and movable with respect to said magnets selectively to short-circuit said magnets, and means on said track for moving said short-circuiting means selectively into and out of short-circuiting engagement with said magnets.

2. A conveyor for articles of magnetic mate rial comprising a carriage, means for moving said carriage over a path, a permanent magnet on said carriage having unlike poles for engaging a magnetizable article on said carriage to retain an article on the carriage, a magnetic conductor on said carriage and movable thereon between a first position in which said conductor is engaged with said magnet to provide a path about said poles while the latter are engaged with .an article to diminish the field applied to said article, and a second position wherein said conductor is disengaged from said poles, and means provided in the path of said movement of said carriage at a predetermined point therein for moving said magnetic conductor selectively into and out of engagement with said poles.

3. A conveyor for articles of magnetic material comprising a conveyor moveable over a path, a carriage on said conveyor, a permanent magnet on said carriage for supporting an article in a position in which the. article depends from the magnet, a magnetic conductor supported on the carriage and moveablethereon between a first position in which said conductor isengaged with said magnet to short-circuit the magnet and reduce flux applied to the article and a second position wherein the conductor is disengaged from said magnet, and means provided in the path of movement of said carriage over said path by said conveyor and engaged during traverse of the conveyor for moving. the conductor into and out of magnet short-circuiting engagement at a predeterminedpoint in said path.

' HOMER D. MERRILL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name a Date 1,141,339 Hodgson June 1, 1915 1,168,281 Buch Jan. 18, 1916 1,487,811 Savage Mar. 25, 1924 1,646,989 Blecker Oct. 25, 1927 1,706,533 Lorig et a1. Mar. 26, 1929 2,117,132 Baermann May 10, 1938 2,204,207 Coburn June 11, 1940 2,243,616 Bing et al May 27, 1941 

